Vessels

Question 1

-What are the 3 types of blood vessels

Answer 1

veins arteries and capillaries

Question 2

What is the Lumen

Answer 2

Lumen is the space within the vessels

Question 3

Rank tunics from innermost to outermost

Answer 3

Tunica intima
Tunica media
Tunica externa

Question 4

Characteristics of the tunica media

Answer 4

◦ Contains smooth muscle cells
◦ Vasoconstriction / vasodilation
◦ Numerous elastic fibers to allow for stretch

Question 5

Characteristics of the tunica externa

Answer 5

◦ Helps anchor vessels to surrounding structures
◦ Can contain vaso vasorum – network of small arteries

Question 6

Companion vessels

Answer 6

vessels that lie next to eachother

Question 7

Arteries compared to other vessels…

Answer 7

Have more collagen and elastic fibers
Additionally they have thicker tunica media and narrower lumen than veins

Question 8

Veins compared to other vessels…

Answer 8

less elastic and collagen fibers
Have thicker tunica externa and larger lumen than arteries
Walls collapse if empty

Question 9

Capillaries compared to other vessels…

Answer 9

thin layer of tunica intima only

Question 10

What is artery branching?

Answer 10

◦ Branch into smaller vessels extending from heart
◦ Decrease in lumen diameter
◦ Decrease in elastic fibers
◦ More smooth muscle in arteries farther away from heart

Question 11

Elastic arteries (conducting)

Answer 11

Largest type of artery
Conduct blood from heart to muscular arteries
◦ Many elastic fibers allowing stretch and recoil
◦ Aorta, pulmonary trunk, common carotid, common
iliac arteries

Question 12

Muscular arteries (distributing)

Answer 12

Medium in size
Most arteries: brachial artery, coronary arteries
◦ Distribute blood to specific body regions
◦ Muscle allows vasoconstriction (and dilation)
◦ Elastic tissue in two layers

Question 13

2 Layers of muscular arteries that have elastic tissue

Answer 13

◦ Internal elastic lamina between intima and media
◦ External elastic lamina between media and externa

Question 14

Arterioles

Answer 14

Smallest
◦ Smooth muscle usually somewhat constricted
◦ Called vasomotor tone (brainstem input)
◦ Regulate systemic blood pressure and blood flow

Question 15

Capillary characteristics

Answer 15

– Small vessels connecting arterioles to venules
o Erythrocytes travel single file (rouleau)
– Optimal thinness for exchange between blood and tissue

Question 16

Continuous Capillaries

Answer 16

◦ Endothelial cells form a continuous lining
◦ Tight junctions connect cells but don’t form
a complete seal
◦ Intercellular clefts are gaps between cells
◦ Large particles (e.g., cells, proteins) cannot
pass, but smaller molecules (e.g., glucose)
can pass through wall
◦ Muscle, skin, lungs

Question 17

Fenestrated capillaries

Answer 17

◦ Endothelial cells have a continuous lining but cells
have fenestrations (pores)
◦ Allows movement of smaller plasma proteins
◦ Found in filtering areas
◦ Intestine, kidney, etc.

Question 18

Sinusoid capillaries

Answer 18

◦ Endothelial cells form an incomplete lining with
large sinusoids (holes)
◦ No basement membrane
◦ Transport of large substances (formed elements,
large proteins)
◦ Bone marrow, spleen, endocrine organs

Question 19

Capillary beds

Answer 19

Group of capillaries that work together

Question 20

Capillary beds are fed by..

Answer 20

metarteriole—a vessel branch of an arteriole

Question 21

The distal part ___________ connects to ___________

Answer 21

thoroughfare channel; postcapillary venule

Question 22

True capillaries

Answer 22

Branches from metarteriole

Question 23

Precapillary sphincter

Answer 23

Smooth muscle ring at true capillary origin

Question 24

Vasomotion

Answer 24

cycle of contracting and relaxing of precapillary sphincters

Question 25

Perfusion

Answer 25

◦ Amount of blood entering capillaries per unit time per gram of tissue ◦ Units are mL/min/g

Question 26

Venules

Answer 26

◦ Companion vessels with arterioles ◦ Merge to form veins very small

Question 27

Small and medium size veins are companion vessels with...

Answer 27

muscular arteries

Question 28

Large veins travel with _______ most veins of this size have ______ preventing _______

Answer 28

elastic arterie; valves; backflow

Question 29

At rest what % of blood is in circulation?

Answer 29

70%

Question 30

What Is the breakdown of systemic circulation at rest

Answer 30

◦ Systemic veins, 55% ◦ Systemic arteries, 10% ◦ Systemic capillaries, 5% additionally ◦ Pulmonary circulation has 18% of blood ◦ Heart has 12% of blood

Question 31

Blood is moved from the veins into circulation via...

Answer 31

vasoconstriction

Question 32

blood is shifted back to the reservoirs by...

Answer 32

vasodilation

Question 33

Simple pathway of blood vessels

Answer 33

◦ One major artery delivers blood to organ or region ◦ Arterioles -> capillary bed -> venule -> major vein -> heart

Question 34

Arterial anastomosis

Answer 34

Two or more arteries converge to supply same region

Question 35

Venous anastomosis

Answer 35

Two or more veins drain same body region

Question 36

Arteriovenous anastomosis

Answer 36

Transports blood from artery directly to vein

Question 37

Portal system

Answer 37

Path: artery -> capillary bed > portal vein > capillary bed > vein

Question 38

Diffusion

Answer 38

substances leave or enter blood according to their concentration gradient (high to low concentration)

Question 39

What is the route diffusion takes place based upon?

Answer 39

Particle size

Question 40

Small solutes diffuse...

Answer 40

through endothelial cells or intercellular clefts

Question 41

Larger solutes pass through...

Answer 41

fenestrations or gaps in sinusoids

Question 41

Vesicular transport

Answer 41

Endothelial cells use pinocytosis and exocytosis ◦ Take substances in by pinocytosis - “cell drinking” ◦ Form fluid-filled vesicles at plasma membrane ◦ Secrete substance from other side by exocytosis

Question 41

Bulk flow

Answer 41

fluids flow down pressure gradient ◦ Large amounts of fluids and dissolved substances move

Question 41

Filtration

Answer 41

fluid moves out of blood (arteriole end) ◦ Fluid and small solutes flow easily through capillary’s openings ◦ Large solutes blocked

Question 42

Reabsorption

Answer 42

fluid moves back into blood ◦ Venule end

Question 43

Bulk flow is driven by:

Answer 43

Hydrostatic pressure and Colloid osmotic pressure

Question 44

Blood hydrostatic pressure (HPb)

Answer 44

◦ Force exerted per unit area by blood on vessel wall ◦ Pressure of blood pushing out of vessel

Question 45

Interstitial fluid hydrostatic pressure (HBif)

Answer 45

◦ Force of interstitial fluid on outside of blood vessel ◦ Pressure of fluid outside of vessel pushing back in

Question 46

Blood colloid osmotic pressure (COPb)

Answer 46

◦ Draws fluid into blood due to blood proteins (e.g., albumins) ◦ Pull of fluid in to vessel

Question 47

Interstitial fluid colloid osmotic pressure (COPif)

Answer 47

◦ Draws fluid into interstitial fluid (usually very low) ◦ Pull of fluid out of vessel

Question 48

Net filtration pressure (NFP)

Answer 48

NFP is the difference between net hydrostatic pressure and net colloid osmotic pressure; that is: NFP = (HPb - Hpif) - (COPb - COPif) (Blood’s push out – Interstitial fluid’s push in) - (Blood’s pull in – Interstitial fluid’s pull out)

Question 49

Net hydrostatic pressure

Answer 49

Difference between blood and interstitial fluid hydrostatic pressures

Question 50

Net colloid osmotic pressure

Answer 50

Difference between blood and interstitial fluid osmotic pressures